Golf club head and golf club

ABSTRACT

A main body portion including a face and a recess formed on a back side of the face, an intermediate member being arranged in the recess, including a first member and a second member, and having a smaller specific gravity than the main body portion, and a high specific gravity member being arranged on a side opposite to the main body portion when viewed from the intermediate member and having a higher specific gravity than the intermediate member are provided.

This nonprovisional application is based on, and claims priority to Japanese Patent Application No. 2014-068479 filed on Mar. 28, 2014 with the Japan Patent Office, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a golf club head and a golf club.

2. Description of the Background Art

In a golf club head, various structures have been employed with respect to a face portion having a ball-hitting portion.

For example, a face portion of a golf club head has been conventionally formed to have a multilayer structure in which a plurality of materials are layered. Japanese Patent Laying-Open No. 2007-160702 discloses a golf club head using a multilayer metal clad plate having a three-layer structure as a face member for the purpose of moderating a shock of an impact while utilizing a repulsive force of a surface layer.

SUMMARY OF THE INVENTION

However, it is difficult to effectively achieve improvement in a ball-hitting feeling with a conventional golf club head including the golf club head disclosed in Japanese Patent Laying-Open No. 2007-160702.

Generally, a golfer cannot have a good ball-hitting feeling when a ball-hitting sound is loud and is less likely to be attenuated. In order to improve the ball-hitting feeling, it is conceivable to provide a thick face portion to suppress a flexure of the face portion at the time of hitting a ball. However, in this case, a disadvantage may arise in that an inertia moment of a golf club head is lowered, so that a rotation of the golf club head is like to occur at the time of hitting a ball and thereby causes a flying distance to be shorter.

The present invention was made to solve the problem described above. A main object of the present invention is to provide a golf club head and a golf club capable of suppressing lowering of the inertia moment while effectively achieving improvement in the ball-hitting feeling.

The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view for illustrating a golf club head and a golf club according to the present embodiment.

FIG. 2 is a cross-sectional view taken along the II-II line in FIG. 1.

FIG. 3 is a cross-sectional view taken along the III-III line in FIG. 1.

FIG. 4 is a cross-sectional view for illustrating a modified example of the golf club head according to the present embodiment.

FIG. 5 is a cross-sectional view for illustrating another modified example of the golf club head according to the present embodiment.

FIG. 6 is a cross-sectional view for illustrating yet another modified example of the golf club head according to the present embodiment.

DETAILED DESCRIPTION

In the following, an embodiment of the present invention will be described with reference to the drawings. It should be noted that the same or corresponding portions in the following drawings have the same reference numerals allotted, and description thereof will not be repeated.

Referring to FIGS. 1 to 3, a golf club and a golf club head 1 according to the present embodiment will be described. The golf club according to the present embodiment has a golf club head 1 connected to one end of a shaft 20. A grip portion is formed at the other end located on a side opposite to the one end of shaft 20. Golf club head 1 according to the present embodiment includes a main body portion 2, an intermediate member 4, and a high specific gravity member 5.

Main body portion 2 includes a face 2A and a recess 3 formed on a back side of face 2A. Face 2A constitutes a ball-hitting face. Main body portion 2 has a hitting position HP on face 2A. Hitting position HP is defined as being within a 10 mm radius circle with a center located on a score line center in a toe-heel direction and at a location of 15 mm above a leading edge (an end portion located on a side of a sole portion 6 of face 2A) along the face.

A plurality of score lines, which are not illustrated, may be formed on face 2A. A material constituting main body portion 2 may be any metal material, and it is for example mild carbon steel (S25C as defined in the JIS standard).

In main body portion 2, at least a part of recess 3 is preferably formed in a region overlapping with hitting position HP of face 2A when viewed from a side of face 2A. A planar shape of recess 3 when recess 3 is viewed in a planar view from the back side of face 2A may be in any shape. However, it preferably has an oblong shape in which a width in a direction from a side of a heel portion 1 h to a toe portion 1 t is larger than a width in a direction from a side of sole portion 6 to a side of a top edge portion 7. Moreover, preferably, a width of recess 3 in a direction from the side of sole portion 6 to the side of edge portion 7 is provided so that it is larger in a region near a central portion 1 c than a region located on a side of heel portion 1 h and toe portion 1 t.

An inner circumferential surface of recess 3 formed along an outer shape of main body 2 on a back side of face 2A is constituted of a bottom surface 3A and a side surface 3B extending in a direction of intersecting bottom surface 3A. A structure of recess 3 can be optionally selected as long as intermediate member 4 can be fixed within recess 3 without a gap. For example, an angle formed between bottom surface 3A and side surface 3B is greater than or equal to 90 degrees, and is preferably an obtuse angle.

Bottom surface 3A of recess 3 is opposite to face 2A across main body portion 2, and is provided as one flat surface. The thickness of main body portion 2 in the region having recess 3 is, for example, greater than or equal to 2.6 mm and less than or equal to 3.4 mm. Side surface 3B may be formed such that a plurality of surfaces intersecting with bottom surface 3A intersect with each other.

Intermediate member 4 is arranged within recess 3. A planar shape of intermediate member 4 when recess 3 is viewed in a plan view from a back side of face 3A can be any shape. However, preferably, it has an oblong shape in which a length in a direction from the side of heel portion 1 h to toe portion 1 t is greater than a length in a direction from the side of sole portion 6 to the side of top edge portion 7.

Intermediate member 4 includes a first member 4 a and a second member 4 b. First member 4 a and second member 4 b are configured to be layered in a direction perpendicular to face 2A. In other words, while first member 4 a is directly connected to bottom surface 3A of recess 3, second member 4 b is not directly connected to bottom surface 3A of recess 3.

A material constituting first member 4 a may be any metal material having a lower specific gravity than main body portion 2 and high specific gravity member 5 which will be described later. The material constituting first member 4 a is, for example, pure titanium (Ti), titanium alloy, aluminum alloy, magnesium alloy, or the like.

A material constituting second member 4 b may be any material having a lower specific gravity than main body portion 2 and high specific gravity member 5 which will be described later, and preferably is a material satisfying the relationship of a specific gravity of second member 4 b<a specific gravity of first member 4 a. The material constituting second member 4 b is, for example, ABS (Acrylonitrile Butadiene

Styrene) resin or epoxy resin. A surface of second member 4 b may be covered with a plated layer (not illustrated). A material constituting the plated layer is, for example, nickel chromium (NiCr). The material constituting the plated layer may be any material. However, when a material having a high specific gravity is used for the plated layer, it is preferable that the film thickness of the plated layer is sufficiently smaller than a width of second member 4 b in a direction perpendicular to face 2A. Moreover, as long as the relationship of a specific gravity described above is satisfied, aluminum alloy or magnesium alloy can be used as second member 4 b.

A specific gravity of first member 4 a which is in proximity to face 2A and connected to main body portion 2 is preferably higher than a specific gravity of second member 4 b connected to high specific gravity member 5. This is because while it is desired on one hand to arrange a metal material directly on face 2A to suppress flexure of the face (main body portion 2), it is also desired on the other hand to reduce a weight of intermediate member 4 as a whole. Therefore, it is preferable that second member 4 b employs a material such as resin having a lower specific gravity than first member 4 a made of a metal material.

Referring to FIG. 2, it is not necessary to render a thickness of first member 4 a in a direction perpendicular to face 2A to be uniform in a direction from the side of sole portion 6 to the side of top edge portion 7. The above-described thickness of first member 4 a is preferably larger on the side of sole portion 6 than on the side of top edge portion 7.

In such a manner, in intermediate member 4 constituted as a composite member, a center of gravity of first member 4 a can be set lower as compared to the case where first member 4 a having a higher specific gravity than second member 4 b is configured as a rectangular parallelepiped. Therefore, a position of a center of gravity of golf club head 1 can be lowered.

Referring to FIG. 3, it is preferable that the thickness of first member 4 a in a direction perpendicular to face 2A is not uniform in a direction from the side of heel portion 1 h to the side of toe portion 1 t through a central portion 1 c. Specifically, the above-described thickness of intermediate member 4 at central portion 1 c is preferably greater than the thickness at heel portion 1 h or toe portion 1 t.

In other words, first member 4 a is thicker near central portion 1 c than on the side of heel portion 1 h and the side of toe portion 1 t. Therefore, the amount of displacement of central portion 1 c which is most likely to be flexed at the time of hitting a ball can be reduced. Accordingly, the ball-hitting sound can be lowered and a good hitting feeling can be obtained.

In this case, the thickness in a direction perpendicular to face 2A of second member 4 b and in the top sole direction is preferably large in the range included in hitting position HP.

Since either first member 4 a and second member 4 b are constituted of a material having a lower specific gravity than main body portion 2 or high specific gravity member 5 as described above, intermediate member 4 as a whole has a lower specific gravity than main body portion 2 or high specific gravity member 5. The thickness of intermediate member 4 in a direction perpendicular to face 2A at the time when intermediate member 4 is fixed to recess 3 is, for example, greater than or equal to 2.5 mm and less than or equal to 10.5 mm.

High specific gravity member 5 is arranged on a side opposite to main body portion 2 when viewed from intermediate member 4. High specific gravity member 5 is joined to at least a part of second member 4 b in intermediate member 4. In other words, high specific gravity member 5 is formed at a position most apart in a backward direction from the side of face 2A in golf club head 1. High specific gravity member 5 may be formed so as to cover an entire surface on a side opposite to the side of face 2A in intermediate member 4, but may also be formed on a region located on the side of sole portion 6 in the above-described surface of intermediate member 4. High specific gravity member 5 is provided so as to overlap with at least a part of recess 3 when golf club head 1 is viewed from a side opposite to face 2A.

High specific gravity member 5 may have any shape, and it has a structure in which a plate-like member is bent. High specific gravity member 5 may be provided with a face located on a side of face 2A and connected to intermediate member 4 and a face located on the opposite side and risen, and the faces are provided, for example, in parallel with each other.

High specific gravity member 5 has a higher specific gravity than intermediate member 4. The material constituting high specific gravity member 5 is a material having a higher specific gravity than intermediate member 4, and it is for example stainless steel (SUS), more preferably a stainless steel strip (SUS304CSP). The thickness of high specific gravity member 5 is, for example, greater than or equal to 0.3 mm and less than or equal to 0.5 mm. It should be noted that the specific gravity of high specific gravity member 5 may be equal to the specific gravity of main body portion 2. As long as the specific gravity of main body portion 2 and the specific gravity of high specific gravity member 5 are substantially equal, the specific gravity of high specific gravity member 5 may be slightly lower or higher than the specific gravity of main body portion 2.

Main body portion 2, intermediate member 4, and high specific gravity member 5 are formed integrally without a hollow portion. In other words, an inner portion of golf club head 1 (each inner portion of main body portion 2, intermediate member 4, and high specific gravity member 5) does not have a hollow portion and has a dense structure.

A connection between main body portion 2 and intermediate member 4 and a connection between intermediate member 4 and high specific gravity member 5 may be provided in any manner as long as main body portion 2, intermediate member 4, and high specific gravity member 5 as one golf club head 1 are not disconnected even at the time of hitting a ball. Main body portion 2 and intermediate member 4 are preferably connected by, for example, press-fitting. Specifically, it is preferable that first member 4 a having a planar shape which is larger than a dimension of recess 3 of main body portion 2 and analogous to a planar shape of recess 3 is press-fitted into recess 3 to connect main body portion 2 and first member 4 a. At this time, first member 4 a is arranged in recess 3 in a state where main body portion 2 is heated and thermally expanded, and thereafter main body portion 2 is cooled and thermally contracted, so that first member 4 a can be press-fitted into recess 3 of main body portion 2. In this manner, a joining strength between main body portion 2 and intermediate member 4 can be enhanced.

First member 4 a and second member 4 b may be joined by means of a double-faced tape. Moreover, second member 4 b and high specific gravity member 5 may be joined by means of a double-faced tape. At this time, a joining interface between first member 4 a and second member 4 b is closer to face 2A than a joining surface between second member 4 b and high specific gravity member 5 and has a large amount of displacement, a double-faced tape for use in joining first member 4 a and second member 4 b is required to have a higher strength than a double-faced tape for use in joining second member 4 b and high specific gravity member 5. Therefore, the double-faced tape for use in joining, for example, first member 4 a and second member 4 b may be thicker than the thickness of the double-faced tape for use in joining second member 4 b and high specific gravity member 5.

Next, the effects of golf club head 1 according to the present embodiment will be described. Golf club head 1 includes main body portion 2 having face 2A and recess 3 formed on a back side of face 2A, intermediate member 4 arranged in recess 3, including first member 4 a and second member 4 b, and having a lower specific gravity than main body portion 2, and high specific gravity member 5 arranged on a side opposite to main body portion 2 when viewed from intermediate member 4 and having a higher specific gravity than intermediate member 4.

In this manner, the thickness of the ball-hitting portion of golf club head 1 configured by connecting main body portion 2, intermediate member 4, and high specific gravity member 5 can be set larger. Accordingly, a ball-hitting sound can be lowered by reducing a flexure of the head caused at the time of hitting a ball, so that a ball-hitting feeling of golf club head 1 can be improved.

At this time, since intermediate member 4 is constituted of a material having a lower specific gravity than main body portion 2, an increase in a mass of golf club head 1 due to thickening of golf club head 1 can be suppressed. Consequently, lowering of the inertia moment in golf club head 1 is suppressed.

Moreover, with respect to intermediate member 4, high specific gravity member 5 constituted of a material having a high specific gravity is provided at a position most apart from face 2A, so that the depth of the center of gravity of golf club head 1 (a distance from the center of gravity of golf club head 1 to face 2A) can be set greater. Consequently, the inertia moment can be set greater than the conventional golf club head not including intermediate member 4. Here, the inertia moment of golf club head 1 represents the inertia moment having an axis on a line extending in a vertical direction through the center of gravity of golf club head 1 and an axis on a line extending in a horizontal direction through the center of gravity of golf club head 1. Accordingly, when a ball is hit at a part deviated from a sweet spot of the golf club head, the deviation from the sweet spot causes golf club head 1 to rotate about the center of gravity, but since the inertia moment of golf club head 1 can be improved, the rotation of golf club head 1 can be suppressed. Consequently, a high stability as to the ball-hitting direction and a flying distance can be achieved.

Moreover, since intermediate member 4 is constituted of first member 4 a and second member 4 b, intermediate member 4 having various characteristics can be obtained by combining materials. For example, also in the case where a material of first member 4 a being close to face 2A and connected to main body portion 2 is limited by the method of connection, constituting second member 4 b with a material having a lower specific gravity than first member 4 a can provide a lower specific gravity as a whole in intermediate member 4.

Preferably, first member 4 a is constituted of a metal material, and second member 4 b is constituted of a resin material. Therefore, since a specific gravity lower than main body portion 2 or high specific gravity member 5 can be provided, the inertia moment can be set greater.

Moreover, recess 3 is formed in the region overlapping with hitting position HP of face 2A when viewed from the side of face 2A, so that the region overlapping with hitting position HP having a great flexure at the time of hitting a ball can be thickened, and the ball-hitting feeling can be improved more effectively.

Moreover, in intermediate member 4, first member 4 a is joined to main body portion 2, and second member 4 b is joined to high specific gravity member 5. In other words, first member 4 a and second member 4 b are preferably configured to be layered in a direction perpendicular to face 2A. Therefore, the variation in the ball-hitting characteristic in face 2A can be suppressed.

Moreover, in the direction from heel portion 1 h to toe portion 1 t, the thickness of a central portion 4 ac of first member 4 a is provided so as to be relatively larger than the thickness of a portion other than central portion 4 ac in first member 4 a (a portion on a side of heel portion 1 h or on a side of toe portion 1 t), and central portion 4 ac of first member 4 a is provided so as to overlap with hitting position HP of face 2A. Accordingly, a flexure of hitting position HP (central portion 1 c) having a large flexure in the direction from heel portion 1 h to toe portion 1 t at the time of hitting a ball can be suppressed effectively, so that the ball-hitting sound can be reduced.

An adhesive may be used to join first member 4 a and second member 4 b and to join intermediate member 4 and high specific gravity member 5.

Moreover, main body portion 2, intermediate member 4, and high specific gravity member 5 are layered continuously without a hollow portion. Therefore, as compared to a golf club head having a hollow portion, a flexure of a golf club head can be suppressed effectively. Consequently, a ball-hitting feeling can be effectively improved with golf club head 1.

Since the golf club according to the present embodiment includes golf club head 1, the inertia moment can be suppressed while effectively achieving the improvement in the ball-hitting feeling.

In intermediate member 4 according to the present embodiment, first member 4 a is joined to main body portion 2, and second member 4 b is joined to high specific gravity member 5, but is not limited to this embodiment.

Referring to FIG. 4, for example, second member 4 b may be joined to main body portion 2, and first member 4 a may be joined to high specific gravity member 5. In other words, golf club head 1 may have a configuration in which second member 4 b, first member 4 a, and high specific gravity member 5 are layered from the side of face 2A in this order in the direction perpendicular to face 2A without a hollow portion. In this case, intermediate member 4 constituted of a material having a lower specific gravity than main body portion 2 is connected to main body portion 2, so that the inertia moment of golf club head 1 can be set greater, and the depth of the center of gravity can also be set greater.

Moreover, referring to FIG. 5, in golf club head 1, recess 3 is formed so as to extend in main body portion 2 from the side of sole portion 6 to the side of top edge portion 7, and intermediate member 4 may be provided in recess 3 from the side of sole portion 6. At this time, main body portion 2 includes a face side main body portion 21 located between face 2A and recess 2 and a back side main body 22 located on a back side of recess 3 when viewed from face 2A.

In this case, in view of the depth of the center of gravity and the inertia moment, it is preferable that the thickness of face side main body portion 21 is provided so as to be smaller than the thickness of back side main body portion 22. Such golf club head 1 has a four-layer structure in which face side main body portion 21, first member 4 a, second member 4 b, and back side main body portion 22 are layered from the side of face 2A in the direction perpendicular to face 2A without a hollow portion. Therefore, as with golf club head 1 described above, the relationship of a specific gravity of second member 4 b<a specific gravity of first member 4 a is satisfied, and the specific gravity of face side main body portion 21 and the specific gravity of back side main body portion 22 can be substantially equal. Consequently, the ball-hitting feeling of golf club head 1 can be improved, and the inertia moment of golf club head 1 can be set greater.

Further, referring to FIG. 6, in golf club head 1, a hole portion 8 which is a closed space being close with respect to main body portion 2 is formed in place of recess 3, and intermediate member 4 may be provided in hole portion 8. Also in this case, in view of the depth of the center of gravity and the inertia moment, it is preferable that the thickness of face side main body portion 21 located between face 2A and recess 3 is provided so as to be smaller than the thickness of back side main body portion 22 located on a back side of recess 3 when viewed from the side of face 2A. Such golf club head 1 has a four-layer structure in which face side main body portion 21, first member 4 a, second member 4 b, and back side main body portion 22 are layered from the side of face 2A in the direction perpendicular to face 2A without a hollow portion. Therefore, as with golf club head 1 described above, the relationship of a specific gravity of second member 4 b<a specific gravity of first member 4 a is satisfied, and the specific gravity of face side main body portion 21 and the specific gravity of main body portion 22 can be substantially equal. Consequently, the ball-hitting feeling of golf club head 1 can be improved, and the inertia moment of golf club head 1 can be greater. It should be noted that, in golf club head 1 shown in FIG. 6, the position at which intermediate member 4 is provided with respect to sole portion 6 is more apart toward the side of top edge portion 7 as compared to golf club head 1 shown in FIG. 5, so that the volume of the region occupied by main body portion 2 is larger near sole portion 6 and smaller near top edge portion 7. Therefore, the position of the center of gravity of golf club head 1 shown in FIG. 6 can be arranged lower than the position of the center of gravity of golf club head 1 toward the side of sole portion 6.

Golf club head 1 shown in FIG. 6 may be formed, for example, by forming a hole in main body portion 2 from the side surface of the side of heel portion 1 h or the side of toe portion 1 t, inserting intermediate member 4 into the hole, and thereafter closing the opening of the hole by means of another member.

Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the scope of the present invention being interpreted by the terms of the appended claims. 

What is claimed is:
 1. A golf club head comprising: a main body portion including a face and a recess formed on a back side of said face; an intermediate member being arranged in said recess, including a first member and a second member, and having a lower specific gravity than said main body portion; and a high specific gravity member being arranged on a side opposite to said main body portion when viewed from said intermediate member, and having a higher specific gravity than said intermediate member.
 2. The golf club head according to claim 1, wherein said first member has a lower specific gravity than said main body portion, and said second member has a lower specific gravity than said first member.
 3. The golf club head according to claim 2, wherein said first member is constituted of a metal material, and said second member is constituted of a resin material.
 4. The golf club head according to claim 1, wherein said recess is formed in a region overlapping with at least a part of a hitting position of said face when viewed from said face.
 5. The golf club head according to claim 1, wherein in said intermediate member, said first member is joined to said main body portion, and said second member is joined to said high specific gravity member.
 6. The golf club head according to claim 1, wherein said main body portion includes a heel portion located at an end portion on a side of a shaft and a toe portion located at an end portion on an opposite side of said heel portion with respect to said face, and in a direction from said heel portion toward said toe portion, a thickness of a central portion of said first member is relatively larger than a thickness of a portion other than said central portion in said first member.
 7. The golf club head according to claim 6, wherein said central portion of said first member is provided so as to overlap with at least a portion of a hitting position of said face.
 8. The golf club head according to claim 1, wherein an adhesive is used to join said first member and said second member and to join said intermediate member and said high specific gravity member.
 9. The golf club head according to claim 1, wherein said main body portion, said intermediate member, and said high specific gravity member are integrally formed without a hollow portion.
 10. A golf club comprising the golf club head according to claim
 1. 